Davis, meanwhile, has taken a different route, reveling in technical puzzles for their own sake. For years, he experimented with techniques for recording visual images on the surface of DNA molecules. Then in 2002, he created the slightly blurred tableau of naked women at right, using tiny particles of gold along with a chemical that binds to DNA only in the presence of visible light. The nude is, of course, a staple of art history; this microscopic image is probably the smallest one ever.